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Date: Mon, 17 May 93 10:16:03 EDT
From: Ralph A.M.J. Wijers <rw@ourania.Princeton.EDU>
Subject: version 6 of 1993J magnitude conflicts list
##
## $Author: rw $
## $Date: 1993/05/06 21:21:52 $
## $Locker: rw $
## $Revision: 1.2 $
## $Source: /amd_tmp/astro/export/home/rw/supernova/RCS/1993j.conflict,v $
##
################################################
# conflicts of 1993j.mag with other lists #
# and other unresolved issues with SN1993J #
# magnitude estimates #
# Version 6 17 May 1993 #
################################################
Here are the conflicts between compilations/reports that I found.
Anyone able to shed light on them is kindly asked to let the
communicity know about it.
general:
========
ALERT: the star reported to be variable by Hanzl (IAUC 5776) is indeed
used in many estimates, e.g. by the Spanish and Norwegian groups. It is
the 10.7 mag star NW of the galaxy, doubly underlined in the Thomson-Bryan chart.
According to gav's report, it is star D in the AAVSO and BAA/The Astronomer
alert charts.
DO NOT use it anymore. If you have past measurements which are based
on this star, please report them. If you had enough stars, revise the
magnitude, if not, preserve the raw data you have. Perhaps the variations
will turn out to be periodic, so we can reconstruct the brightness at any
given time and revise the magnitudes from the raw data.
Taichi Kato's list:
-- info on errors?
Bjorn Granslo's list: many cases where I noted TB as reference from regular
updates sent on behalf of the Norwegian Variable Star
observers have TA as reference in his compilation. Why?
Spain: the discovery group, Garcia, Pujol, Ripero:
If I plot their measurements for comparison with all the others, it
seems that from 04/01 to 04/06, they are in line with the rest,
from 04/06 to 04/12, they are significantly fainter, and from 04/12 on
they are significantly brighter. I did not yet make such plots for
all other observers, but from what I saw sofar, theirs seem strange.
Since their early points are almost the only early ones we have,
I feel we should make some effort to sort this out.
It should be noted that Rodriguez's CCD measurements are off in
exactly the same sense as the visual estimates of the group.
This makes me suspect that at least part of the deviation could be a
matter of comparison stars.
Update 19930426: I got a message from
Bjorn Granslo, who received a fax from Ripero, listing
all Spanish measurement on or before March 31. This clears up
a lot of confusion. The measurements that are now in my list
are the only correct ones, all other times/magnitudes should
discarded.
Update 19930506: we now have the raw estimates for the early
Spanish measurements, and apart from some of them using the possibly
variable star D (mv = 107 on TB chart), they are OK.
Nothing new on the later ones.
specific entries:
=================
Note: all items containing a "resolution(Date)" will be gone in the next
version.
03 31.972 Munari 10.84 V IAU 5750, grl \ munari given precedence, as
03 31.972 Sostero 11.06 V IAU earlier / he reports correction to
sostero explicitly.
followup (19930506): IAU Circular 5750 actually gives the
value as 10.94 (as in Kato's list) --sorry
resolution (19930517): 10.94 now accepted by all
04 01.083 Schmeer Germany 10.7 0 TB SELF \ In the email I got from
04 01.083 Schmeer Germany 10.7 0 AC kat / he quotes the "Supernova
Search Chart" = TB for all his measurements. The sequence listed by
Kato/Granslo for his data varies from point to point. I think we
have to quote TB for all of them.
followup (19930506): TB accepted for this measurement. Some later
data by Schmeer are quoted as TA, perhaps
he could clarify the issue himself?
04 05.15 Levy 12.1 mv TB SELF 04/XX \ Levy accepted, because he correc-
04 05.15 Levy 11.6 mv gmh 04/14 / ted his 11.6 estimate personally.
followup (19930506): Granslo and Kato lists still give 11.6. To
convince everyone of the correctness of 12.1,
here is a piece of his email to me:
>> I'd earlier posted an estimate on April 5.15 of ".2 mag fainter than B"; I
>> was calling star B mag 11.4, which seems to be its GSC tabulated V brightness,
>> and so called SN1993J mv 11.6. Michael's recent note calls B mv 11.9 not 11.4
>> (quoted from T&B); I'd like to revise my estimate accordingly. So:
>>
>> Date SN1993J mv System
>> April 5.15 12.1 "TB & Richmond"
>> April 10.14 11.2 "TB & Richmond"
>>
>> Stuart Levy, Geometry Center, University of Minnesota
followup (19930517): Granslo and Kato lists still give 11.6.
04 06.140 Beauchamp 11.7 mv TB SELF \ self given precedence
04 06.099 Beauchamp 11.7 mv TB grl 04/18 /
followup (19930506): Kato now lists both, Granslo lists 06.140.
I kept both as well, but I re-checked my
mail, and only have Beachamp's report for
06.140. I will therefore remove 06.099
in version 6, unless Beauchamp says otherwise.
followup (19930517): Situation unchanged. I deferred deleting the 6.099
data, until I get a reply from Beauchamp about
the matter.
04 16.524 Funada 10.9 mv TB kat 04/21 \ Kato accepted as primary source
04 16.524 Funada 10.8 mv TB grl 04/18 /
followup (19930506): Granslo still lists 10.8. Could Granslo
and/or Kato comment on this?
resolution (19930517): Granslo now also lists 10.9.
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